TWI478525B - Dynamic adaption of transmission rate for multiuser mimo networks - Google Patents

Description

Transmission rate dynamic adjustment mechanism for multi-user multi-antenna systems

The present invention relates to a transmission rate dynamic adjustment mechanism of a multi-user multi-antenna system, and more particularly to a transmission rate adjustment method of a communication device under the mechanism, a data transmission control method and a data transmission control apparatus of the wireless communication system.

The two mainstream trends in wireless networks are: in response to the increasing number of antennas supported by wireless routers, the development of wireless data transmission systems that support most antennas, and multi-antenna devices that support clients, forming a multi-user multi-antenna network system. In this multi-input multi-output system (MU-MIMO system), many users use multi-antenna client devices while sharing the frequency of a single multi-antenna router. Wide resources.

In a conventional wireless network, only one user is allowed to transmit signals in a single time. At this time, the transmission rate is related to the channel characteristics between the user equipment and the wireless transceiver. Since the channel characteristics will only change slightly over a period of time, the transmission rate is determined based on the recorded past optimal transmission rate. The transmitting end selects the best transmission rate in the past to transmit the data. After selecting the transmission rate, use this information to encode the data and set the corresponding header. The receiving end can retrieve the original data by using the information provided by this header.

In order to meet the needs of multi-user multi-antenna systems, the current state of the art is to change the design of the decoder at the receiving end. When decoding signals, ZF-SIC (Zero-Forcing Successive Interference Cancellation) is used to enable routers to use the characteristics of MIMO to transmit signals from two user devices when two user devices simultaneously transmit signals. Resolve to achieve the goal of multiple users simultaneously transmitting data over the wireless network.

However, the prior art method does not consider the impact of the selected transmission rate in the MIMO system, but simply selects an optimum transmission rate known to the user equipment as the transmission rate. It is known from the recently published technical literature that in MU-MIMO, the optimal transmission rate of the user equipment is not only related to its own channel characteristics, but also closely related to the channel characteristics of other devices transmitted at the same time. At the same time, in the MU-MIMO environment, the simultaneously transmitted user equipment is not fixed, but has quite frequent changes. Each packet may be transmitted with a packet of a different user device. Therefore, to achieve the correct rate of selection for each packet, it becomes a very important issue. In other words, if the transmission rate selected by the transmitter is too high, the receiver will not be able to solve the packet at all. In addition, in the MU-MIMO environment, it is more remarkable that selecting the wrong transmission rate not only affects its own packet, but also causes the packets sent by other simultaneous transmitters to be decoded correctly. As a result, it is not only impossible to increase the transmission rate, but it will cause the entire network to fail, and it will not transmit or decode any message.

It is an object of the present invention to provide a transmission rate dynamic adjustment mechanism for a multi-user multi-antenna system that allows the user equipment to select an optimal data transmission rate in a multi-user multi-antenna system.

The object of the present invention is to provide a transmission rate dynamic adjustment mechanism for a multi-user multi-antenna system, which can dynamically select the optimal data transmission rate for most user equipment in a multi-user multi-antenna system.

The first aspect of the transmission rate adjustment of the multi-user multi-antenna system of the present invention relates to a transmission rate adjustment method of a communication device having two antennas, that is, the wireless transceiver allows only two communication devices to transmit at the same time, which is convenient for reading. A person transmitting data is referred to as a first communication device, and a second person transmitting data is referred to as a second communication device. The method includes the following steps: all communication devices use a method of reciprocity to calculate respective to a wireless transceiver when the wireless receiver broadcasts a signal Channel information, and thereby calculating respective signal noise ratio SNR _ori ; the first communication device transmits the signal to the wireless transceiver according to the original transmission rate; the first communication device broadcasts the message between the channel and the wireless transceiver; The communication device detects the first communication device and the wireless transceiver to transmit the data and receives the channel information transmitted by the communication device; the second communication device determines, according to the relationship between the channel and the channel of the first communication device, the communication device transmits the data Signal noise ratio SNR _proj ; and second communication device based on the resulting noise ratio SNR _{p Roj} adjusts the rate selected at the time of the original transmission so that the second communication device transmits the data without affecting the first communication device.

The relationship between the channel of the first communication device and the second communication device is between the channel direction (h ₁ ) of the first communication device to the wireless transceiver and the channel direction (h ₂ ) of the second communication device to the wireless transceiver. The angle θ ‧ wherein the signal noise ratio SNR _proj can be calculated from the signal angle θ according to the following equation: SNR _proj = SNR _ori × sin ² (θ). The signal transmitted by the second communication device at the rate selected by the SNR _{proj is a} rate that does not interfere with the transmission of data by the first communication device.

In order to increase the usage rate of the wireless network, the data transmission is terminated simultaneously with the communication device of the wireless transceiver after a predetermined time, and the same steps are repeated to continue the data transmission.

The second aspect of the present invention relates to a data transmission control method for a wireless communication system with three antennas, that is, the wireless transceiver allows only three communication devices to transmit at the same time, which is convenient for reading. The first transmitting material is referred to as a first communication device, the second transmitting material is referred to as a second communication device, and the third transmitting material is referred to as a third communication device. The method includes the following steps: all communication devices broadcast signals at a wireless receiver The reciprocity method is used to calculate the channel information of each of the wireless transceivers, and the respective signal to noise ratio SNR _{ori is} calculated by the first communication device; the first communication device broadcasts the channel information; The second communication device detects the channel information transmitted by the first communication device to the wireless transceiver and knows the channel information of the first communication device broadcast by the first communication device; the second communication device utilizes the first The method mentioned adjusts the transmission rate; the second communication device transmits data to the wireless transceiver; the second communication device Broadcasting a channel message between itself and the wireless transceiver device; when the second communication device broadcasts its channel message, the first communication device stops transmitting data to the wireless transceiver; during the time when the first communication device stops transmitting data, the second communication device Broadcasting the channel information so that the third communication device knows the channel information transmitted by the second communication device to the wireless transceiver; and the first and second communication devices resume the original data transmission after the second communication device completes broadcasting the channel information of the channel The third communication device determines the signal-to-noise ratio SNR _{proj of the} data transmitted by the third communication device according to the channel information of the first communication device, the channel information of the second communication device, and the channel information of the third communication device; and the third communication The device adjusts the transmission rate according to the obtained noise ratio SNR _proj , so that the third communication device does not affect the signals transmitted by the first communication device and the second communication device; wherein the SNR _proj can be a channel between the third communication device and the wireless transceiver ( h ₃ ) and the channel between the first and second communication devices and the wireless transceiver (h ₁ , h ₂ ) is pushed and pushed, and the angle is θ is h ₃ for the angle between the planes formed by h ₁ and h ₂ , and the signal noise ratio SNR _{proj of the} third communication device can be calculated according to the following equation: SNR _proj = SNR _ori × sin ² (θ). The third communication device transmits the data using the transmission rate selected by the SNR _proj without interfering with the rate at which the first and second communication devices transmit data.

In order to increase the usage rate of the wireless network, the data transmission is terminated simultaneously with the communication device of the wireless transceiver after a predetermined time, and the same steps are repeated to transmit the data.

The third aspect of the multi-user multi-antenna system of the present invention relates to a data transmission control device for controlling a wireless communication system, the system comprising a transceiver device with more than four antennas, which can be performed with most communication devices The data transmission makes the number of antennas of the wireless transceiver device N, that is, the wireless transceiver allows only N communication devices to transmit at the same time, and the first transmission device is called the first communication device for the convenience of reading the first transmission data, and the second transmission data is called a second communication device, the third transmission material is referred to as a third communication device, ..., the Nth transmission material is referred to as an Nth communication device, and the control device includes the following steps: All communication devices are wireless When the receiver broadcasts the signal, the reciprocity method is used to calculate the channel information of each of the wireless transceivers, and the respective signal to noise ratio SNR _{ori is} calculated; the first communication device transmits the data to the wireless transceiver; the first communication device broadcasts Channel information; the second communication device detects channel information transmitted by the first communication device to the wireless transceiver and learns that the first communication is a channel message of the first communication device broadcast by the device; the second communication device adjusts the transmission rate using the method already mentioned in the second aspect; the second communication device transmits the data to the wireless transceiver; and the second communication device broadcasts the data During the channel message, the first communication device stops transmitting data to the wireless transceiver; during the stop of the transmission of the data by the first communication device, the second communication device broadcasts the channel information so that the remaining communication device knows that the second communication device transmits and receives the data to the wireless device. The channel information transmitted by the device; the first and second communication devices resume the original data transmission after the second communication device completes broadcasting the channel information of the channel; the Kth (K is smaller than N) communication device detects the first K-1 communication The channel information transmitted by the device to the wireless transceiver and the channel information of all the broadcasts thereof; the Kth communication device adjusts the transmission rate by using the angle between the channel formed by the channel and the channel of the front K-1 communication device; The communication device transmits the data to the wireless transceiver using the selected transmission rate; the front K-1 communication device stops transmitting the data to the wireless transceiver; During the K-1 communication device stops transmitting data, the Kth communication device broadcasts the channel information, so that the communication device after K knows the channel information transmitted by the Kth communication device to the wireless transceiver; the first K communication devices are at the Kth After the communication device completes broadcasting the channel information of the channel, the original data transmission is resumed; the Nth communication device determines the signal noise of the data transmitted by the Nth communication device according to the relationship between the channel information of the previous N-1 communication device and its own channel information. Ratio SNR _proj ; the Nth communication device adjusts the transmission rate according to the obtained noise ratio SNR _proj such that the Nth communication device does not affect the signal transmitted by the front N-1 communication device; and wherein the SNR _proj can be shared by the Nth communication device The channel (h _N ) between the wireless transceivers is derived from the channel (h ₁ ~h _N-1 ) between the front N-1 communication device and the wireless transceiver, and the angle θ is h _N for h ₁ ~h _N-1 The angle between the planes is formed, and the signal-to-noise ratio SNR _{proj of} the Nth communication device can be calculated according to the following equation: SNR _proj = SNR _ori × sin ² (θ). The Kth communication device transmits data using the transmission rate selected by SNR _proj without interfering with the rate at which the first K-1 communication devices transmit data.

In order to increase the usage rate of the wireless network, the data transmission is terminated simultaneously with the communication device of the wireless transceiver after a predetermined time, and the same steps are repeated to continue the data transmission.

In the present invention, the signal channel direction h _n may be a channel vector of the communication device transmitting a signal to the antenna of the transceiver, h _n = (h _n1 , h _n2 , . . . , h _nm ), where n is a natural number , m table the number of antennas of the transceiver. Hn1,h _n2 ,...,h _nm is a complex number, which can be expressed as a+bi, a, b R, this value can be measured by the instrument.

1‧‧‧Wireless transceiver

2‧‧‧First communication equipment

3‧‧‧Second communication equipment

4‧‧‧ Third communication equipment

11, 12‧‧‧ antenna

Fig. 1 is a diagram showing an application system for dynamically adjusting the transmission rate of the multi-user multi-antenna system of the present invention.

Figure 2A shows a schematic diagram of the application of the ZF-SIC method in an embodiment of the invention.

Figure 2B shows a schematic diagram of the ZF-SIC method when the connected communication device changes.

FIG. 3 is a flowchart of a first embodiment of a data transmission control method for a wireless communication system according to the present invention.

4 is a flow chart of a second embodiment of a data transmission control method for a wireless communication system of the present invention.

Figure 5 is a graph showing a comparison of the total transmission rate of the present invention applied to a dual antenna system and a known technique.

Figure 6 is a graph showing a comparison of the total transmission rate of the present invention applied to a three-antenna system and a known technique.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the dynamic adjustment of the transmission rate of the multi-user multi-antenna system of the present invention will be described with reference to the drawings. It is to be understood that the preferred embodiments of the invention are merely illustrative of the invention. The possible application modes and application scope of the present invention are not limited to the illustrated embodiments. It is not difficult for the practitioner to make various changes and extensions in accordance with the description of the present invention. However, it should be within the scope of the invention without departing from the spirit of the invention.

Fig. 1 is a diagram showing an application system for dynamically adjusting the transmission rate of the multi-user multi-antenna system of the present invention. The figure shows a multi-user multi-antenna wireless communication system having a wireless transceiver 1 for data exchange with a plurality of communication devices 2, 3, 4. The wireless transceiver 1 can be any multi-antenna wireless transceiver supporting multiple users, such as a network router, a base station, a sharer, and the like. In this case, the communication devices 2, 3, 4 may be computers with wireless communication capabilities, notebook computers, smart phones, personal digital assistants, tablets or other wireless transceivers, and the like.

The figure shows that the first communication device 2 and the second communication device 3 are being wired to the wireless transceiver 1. The two antennas 11 and 12 of the wireless transceiver 1 simultaneously receive the data sent by the first communication device 2 and the second communication device 3. At this time, the wireless transceiver 1 needs to parse out the data sent by the first communication device 2 and the second communication device 3 from the received signals. This method of analysis has been proposed by many experts, but the most commonly used method is the ZF-SIC (Zero-Forcing Successive Interference Cancellation) method described above. The law is described below.

After the wireless transceiver 1 first establishes a connection with the first communication device 2, the first communication device 2 will transmit the information stream to the wireless transceiver 1 at a rate. The rate at which the first communication device 2 transmits data is set to a second rate. This second rate can be determined in any suitable manner. In general, the optimum transmission rate in the recording of the first communication device 2 is selected. This rate can be directly looked up using SNR to derive the optimal transfer rate. The method has been proposed in other papers. Assuming that the wireless transceiver 1 has two antennas 11 and 12, the signal string sent by the first communication device 2 can be projected onto the plane defined by the two antennas to become a vector h ₁ = (h ₁₁ , h ₁₂ ). Thereafter, the wireless transceiver 1 also establishes a connection with the second communication device 3. The second communication device 3 will transmit the information stream to the wireless transceiver 1 at a rate. The rate at which the second communication device 3 transmits data is set to a first rate. The first rate can be determined by any suitable method, such as the optimal transmission rate in the record. At this time, the wireless transceiver 1 can project the received data string to the direction perpendicular to the channel direction t of the first communication device 2 by the Zero-Forcing method, and the second communication device 3 can be solved. data.

With the above-described projection method, the wireless transceiver 1 can remove the influence received by the signal transmitted by the first communication device 2 from the signal received by the second communication device 3 to perform correct decoding. In addition, the wireless transceiver 1 also re-decodes the signal string sent by the first communication device 2 by the method of Successive Interference Cancellation, that is, removes the signal component of the second communication device 3, leaving the original first communication device. The separate signal is then decoded. The above method is the so-called ZF-SIC method and is widely used in the industry. Fig. 2A shows a schematic diagram of the application of the ZF-SIC method in the embodiment of the present invention.

In the above processing, if the signal decoding of the second communication device 3 is erroneous, the decoding of the signal of the first communication device 2 will be impaired. Since the wireless transceiver 1 cannot correctly transmit the signal from the first communication device 2, the signal component of the second communication device 3 is removed.

Further, in the above processing, the signal of the second communication device 3 is caused to attenuate the intensity due to the projection of the signal of the second communication device 3. At this time, if the first communication device 2 cannot adjust its data transmission rate, its communication quality will be lost. The past technology does not provide a solution to this technical problem, so the second communication device 3 can only continue to use its original data transmission rate, and after a period of time, the wireless transceiver 1 re-accepts the respective communication devices 2, 3. 4, the competition so far. This will cause all the signals to be unsolved, but will reduce its effectiveness.

It can also be inferred from FIG. 2A that when the wireless transceiver 1 simultaneously connects with the second communication device 3 and the third communication device 4 and simultaneously transmits data, the communication quality of the second communication device 3 is completely different from that of FIG. 2A. . This is shown in Figure 2B. In the case of FIG. 2B, the second communication device 3 can use a higher transmission rate than the case of FIG. 2A because the second communication The angle between the device 3 and the signal path of the third communication device 4 is relatively large.

Although the present invention is not limited to any technical theory, according to the findings of the present inventors, the data transmission quality of the second communication device 3 is directly affected by the first communication device 2, and thus the originally set communication rate may be Does not match the requirements. The influence of the first communication device 2 on the communication quality of the second communication device 3, that is, the data noise ratio SNR, can be calculated according to the signal channel direction of the two communication devices. In detail, the communication SNR of the second communication device 3 becomes SNR _proj under the influence of the signal of the first communication device 2, and can be calculated as follows: SNR _proj = SNR _ori × sin ² (θ) (1), wherein SNR _proj : signal strength (SNR) when the second communication device 3 is decoded by the wireless transceiver 1; SNR _ori : signal strength (SNR) when the second communication device 3 is separately transmitted θ: the second communication device 3 and other communication devices The angle between the spaces formed by the signal paths h ₁ , h ₂ , ..., h _n .

Wherein, the signal channel direction h _n is a channel vector of each communication device transmitting a signal to the antenna of the transceiver, h _n =(h _n1 , h _n2 , . . . , h _nm ), n is a natural number, m table The number of antennas in the transceiver. h _n1 is a complex number and can be expressed as a+bi, a, b R, this value can be measured by the instrument. See Figure 2A for an illustration of the angle of the signal path.

In the present invention, the SNR (SNR _ori ) when the communication device is separately transmitted can be calculated by means of reciprocity. In practical applications, the wireless transceiver 1 can periodically send a signal, and each communication device 2, 3, 4 can estimate the signal strength SNR _ori when it is transmitted alone according to the signal. This application technique has been extensively described in the currently available papers. In short, the channel from each communication device to the wireless transceiver 1 and the channel from the wireless transceiver 1 to each communication device have an integer multiple relationship with each other. Therefore, based on the signal received from the wireless transceiver 1, the signal characteristics of the particular communication device itself transmitted to the wireless transceiver 1 can be estimated. Therefore, the technology is known in the industry, and the details thereof need not be described here.

When calculating the angles of the signal channels between the different communication devices 2, 3, 4, the first communication device 2 to the transmission opportunity can be broadcasted in a specific time to make its own signal direction, so that other communication devices 3, 4 can be utilized. The signal channel direction information is calculated according to the above formula, and the actual signal strength SNR _proj at that time is calculated.

Since the actual signal strength SNR _{proj is} known, the second communication device 3 can correct its data transmission rate based on the actual signal strength SNR _proj value to optimize its signal strength. The correction method may use any known method, but in the preferred embodiment of the present invention, it is possible to reduce or improve itself within a possible range that does not affect the data transmission quality of other communication devices (such as the first communication device 2). Transmission rate. Other methods of adjusting the data transmission rate can also be applied to the present invention.

Therefore, in the above example, the steps of the data transmission control method of the wireless communication system of the present invention can be explained as follows with reference to FIG. FIG. 3 is a flowchart of a first embodiment of a data transmission control method for a wireless communication system according to the present invention:

In step 301, all communication devices use the reciprocity method to calculate the channel information of each of the wireless transceivers when the wireless receiver broadcasts the signal, and calculate the respective signal to noise ratio SNR _ori . In step 302, the first communication device 2 transmits the data to the wireless transceiver 1. In step 303, the first communication device 2 broadcasts the channel information. In step 304, the second communication device 3 detects the channel information broadcast by the first communication device 2 and calculates a signal to noise ratio SNR _proj when the data is transmitted together with the first communication device 2. In step 305, the second communication device 3 adjusts the transmission rate using SNRproj and starts transmitting data. At step 306, the communication with the wireless transceiver ends its data transmission at the same time. In this embodiment, the signal noise ratio SNR _proj obtained by the method of Equation 1 is used to calculate the transmission rate.

As for the transmission rate adjustment method of the communication device of the present invention, the second communication device 3 of the above example is used, and the transmission rate is adjusted according to the signal channel direction of the first communication device 2. Its content does not need to be described.

However, in the above example, if the wireless transceiver 1 can support 3 or more communication devices to simultaneously transmit data, after the first communication device 2 and the second communication device 3 have reached a connection, the third communication device 4 is even The wireless transceiver 1 establishes a connection and still cannot calculate the actual signal strength SNR _{proj of} the third communication device 4 under the coexistence of the first communication device 2 and the second communication device 3. The main reason is that the third communication device 4 cannot receive the channel information of the second communication device 3, because the current communication device often has only one antenna, if the first communication device still broadcasts the channel information when the second communication device broadcasts the channel information. When the data is transmitted, the signal mixed by the first communication device and the second communication device cannot be solved; the signal received by the third communication device 4 includes the signal component of the first communication device 2 and the signal component of the second communication device 3.

To solve this problem and to provide a case where the present invention is applied to simultaneous transmission of three or more communication devices, the second embodiment of the present invention provides a mechanism. That is, in most (3 or more) communication devices, the channel information that has been added to the transmitting communication device can still be known to adjust its own transmission rate. The implementation method of this embodiment will be described below by taking the case of three sets of communication devices as an example. The situation of more than three groups can be derived from the deduction of this example.

4 is a flow chart of a second embodiment of a data transmission control method for a wireless communication system of the present invention. This method is suitable for applications that support 3 or more communication devices. As shown, the method includes the following steps:

In step 401, all the communication devices use the reciprocity method to calculate the channel information of each channel to the wireless transceiver when the wireless receiver broadcasts the signal, and calculate the respective signal to noise ratio SNR _ori . In step 402, the first communication device 2 transmits the data to the wireless transceiver 1. In step 403, the first communication device 2 broadcasts the channel information. In step 404, the second communication device 3 and the third communication device 4 detect the channel information transmitted by the first communication device 2 to the wireless transceiver 1, and the second communication device calculates its own SNRproj. In step 405, the second communication device 3 adjusts the transmission rate to the wireless transceiver 1 using SNRproj and starts transmitting data. In step 406, the second communication device broadcasts a channel message with the wireless transceiver, and the first communication device 2 suspends its data transmission at this time, for example, a null signal is transmitted. During the time when the first communication device 2 stops transmitting data, the second communication device 3 broadcasts the channel information in step 407, and the third communication device 4 detects the channel information transmitted by the second communication device 3 to the wireless transceiver 1. At this time, the third communication device has learned the channel information of the first and second communication devices and calculates SNRproj. In step 408, the first and second communication devices resume the original data transmission. In step 409, the third communication device 4 adjusts the transmission rate of the self according to the obtained noise ratio SNR _proj and starts transmitting data.

The method may further include the step 410 of stopping the receiving device from accepting the data transmission by the plurality of communication devices after the predetermined time to reopen the competition of the plurality of communication devices.

In the above control, the first communication device transmits according to the transmission rate selected at the time of the original transmission; the second communication device simultaneously considers the channel between itself and the first communication device, calculates the SNR _proj , and selects by using the lookup table. The best transmission rate of the self; the third communication device considers its own channel with the first and second communication devices, calculates the SNR _proj , selects its own transmission rate by means of look-up table, and so on.

The data transmission control device of the present invention is for controlling a wireless communication system, and the system comprises a transceiver device having two or more antennas for data transmission with a plurality of communication devices. The control method of the control device is the step shown in Fig. 4.

In order to prove the effect of the present invention, an infinite transceiver of two antennas (supporting two sets of communication devices) and an infinite transceiver of three antennas (supporting three sets of communication devices) are respectively decoded by the method of the present invention according to the self-calculated signal. The SNR, the method of selecting the transmission rate, and the traditional 802.11 method are tested separately. The results are shown in Figures 5 and 6. Among them, Fig. 5 shows a comparison between the SNR selection transmission rate of the self-transmitted signal and the total transmission rate (mbps) of the conventional 802.11 applied to the dual antenna system. Figure 6 shows the application of the three-antenna system. The present invention compares the transmission rate of the SNR with its own transmitted signal with the total transmission rate (mbps) of the conventional 802.11. The figure shows that the total transmission rate of the present invention is 1.7 times (two-antenna system) and 2.3 times (three-antenna system) of the conventional method. In MU-MIMO, if the problem of rate selection during transceiver decoding is not considered, as shown in the figure "Selecting the transmission rate by SNR of its own transmission signal", the communication device may select a transmission rate that makes the router completely unable to decode, resulting in a transmission rate. The transmission rate is reduced to zero.

Claims (20)

A method for adjusting a transmission rate of a communication device, the method comprising the steps of: calculating, by using a reciprocity method, a channel information of each of the communication devices to the wireless transceiver when the wireless receiver broadcasts the signal, and calculating a respective signal to noise ratio SNR _ori ; a communication device transmits data to a wireless transceiver at a transmission rate when transmitted separately; detects another communication device that transmits data to the wireless transceiver and receives channel information transmitted by the other communication device; The relationship between the channel information and the channel information of the other communication device, determining the signal-to-noise ratio SNR _{proj of the} data transmitted by the communication device; adjusting the rate according to the obtained noise ratio SNR _proj , and starting to transmit the data; After the time, the communication device of the wireless transceiver ends its data transmission at the same time. The method of claim 1, wherein the relationship between the channel information and the channel information of the other communication device is that the communication device sends the wireless transceiver signal to the other communication device in the direction of the signal path of the wireless transceiver. The angle θ of the channel direction. The method of claim 2, wherein the signal channel direction h _n is a channel vector of the communication device transmitting a signal to the antenna of the transceiver, h _n =(h _n1 , h _n2 , . . . , h _nm ), n is a natural number, and m is the number of antennas of the transceiver. The method of claim 2, wherein the signal noise ratio SNR _{proj is expressed} by the following equation: SNR _proj = SNR _ori × sin ² (θ). The method of claim 1, wherein the communication device utilizes the adjusted rate to not interfere with the rate at which the other communication device transmits data. A data transmission control method for a wireless communication system, the method comprising the steps of: using a reciprocity method to calculate channel information of each of the wireless transceivers when the wireless receiver broadcasts the signal, and calculating respective signal noises by using the method of reciprocity Ratio SNR _ori ; the first communication device transmits data to a wireless transceiver at a transmission rate when transmitting alone; the first communication device broadcasts its channel information; and the second communication device detects the signal of the first communication device, and is first The communication device broadcasts the channel information; the second communication device determines the signal-to-noise ratio SNR _{proj of the} data transmitted by the second communication device according to the relationship between the channel information and the channel information of the first communication device; and the second communication The device adjusts its own transfer rate and starts transmitting according to the resulting noise ratio SNR _proj . The method of claim 6, wherein the relationship between the self channel information and the channel information of the other communication device is that the communication device is in the direction of the wireless transceiver signal channel (h ₁ ) to the other communication device pair. The angle θ of the wireless transmission and reception signal channel direction (h ₂ ). The method of claim 7, wherein the signal channel direction h _n is a channel vector of the communication device transmitting a signal to the antenna of the transceiver, h _n =(h _n1 , h _n2 , . . . , h _nm ), n is a natural number, and m is the number of antennas of the transceiver. The method of claim 7 or 8, wherein the signal noise ratio SNR _proj is calculated from the signal angle θ according to the following equation: SNR _proj = SNR _ori × sin ² (θ). As in the method of claim 6, the second communication device transmits the data at the transmission rate selected by the SNR _proj without affecting the signal of the first communication device. A data transmission control method for a wireless communication system, the method comprising the steps of: using a reciprocity method to calculate channel information of each of the wireless transceivers when the wireless receiver broadcasts the signal, and calculating respective signal noises by using the method of reciprocity Ratio SNR _ori ; the first communication device transmits data to a wireless transceiver at a transmission rate when transmitting separately; the first communication device broadcasts the channel information; and the second and third communication devices detect the first communication device to transmit and receive the data to the wireless device Channel information transmitted by the second communication device; after learning the channel information of the first communication device, calculating SNR _proj and starting to transmit data; the second communication device broadcasting the channel information, during which the first communication device stops the wireless transceiver Transmitting data; the third communication device detects channel information transmitted by the second communication device to the wireless transceiver; and the first and second communication devices resume data transmission after the second communication device broadcasts the channel message; and the third communication device According to the relationship between the channel information of the first and second communication devices and the channel information of the first communication device, Disconnecting the signal to noise ratio SNR _{proj of} the third communication device to transmit data; the third communication device adjusts the transmission rate of the self according to the obtained noise ratio SNR _proj and starts transmitting data; and after a predetermined time, all communication devices simultaneously terminate the same Data transfer. The method of claim 11, wherein the relationship between the third communication device and the channel information of the first communication device and the second communication device is the channel direction h ₃ of the third communication device to the wireless transceiver, the first and the The angle θ between the planes formed by the channel directions h ₁ and h _{2 of} the communication device. The method of claim 12, wherein the signal channel direction h _n is a channel vector of the communication device transmitting a signal to the antenna of the transceiver, h _n =(h _n1 , h _n2 , . . . , h _nm ), n is a natural number, and m is the number of antennas of the transceiver. The method of claim 12, wherein the signal noise ratio SNR _proj is calculated according to the following equation: SNR _proj = SNR _ori × sin ² (θ). The method of claim 11, wherein the adjusted communication rate of the third communication device does not interfere with the rate at which the first and second communication devices transmit data. A data transmission control device for controlling a wireless communication system, the system comprising a transceiver device having three or more antennas, wherein N represents the number of antennas of the transceiver device, and data transmission can be performed with N communication devices; The control of the device includes the following steps: when the wireless receiver broadcasts the signal, all the communication devices use the method of reciprocity to calculate the channel information of each of the wireless transceivers, and calculate the respective signal to noise ratio SNR _ori ; thereby making the first communication device Transmitting the data to the wireless transceiver; causing the first communication device to broadcast the channel information; and detecting, by the second communication device, the channel information transmitted by the first communication device to the wireless transceiver and learning that the first communication device broadcasts Channel information of the first communication device, calculating SNR _proj ; causing the second communication device to adjust the transmission rate by using SNR _proj ; causing the second communication device to transmit data to the wireless transceiver; and causing the second communication device to broadcast its own channel with the wireless transceiver The message is that when the second communication device broadcasts its channel message, the first communication device stops the The transceiver transmits the data; during the stop of the transmission of the data by the first communication device, the second communication device broadcasts the channel information such that the remaining communication device knows the channel information transmitted by the second communication device to the wireless transceiver; the first and second communications After the second communication device completes broadcasting the channel information of the channel, the device restores the original data transmission; and the K (K is smaller than N) communication device detects the channel information transmitted by the former K-1 communication device to the wireless transceiver. Knowing the channel information broadcasted by the K-channel communication device, using the angle between its own channel and the space formed by the channel of the front K-1 communication device, calculating the SNR _proj to adjust the transmission rate; and making the Kth communication device utilize the selection The transmission rate transmits data to the wireless transceiver; the Kth communication device broadcasts a channel message between itself and the wireless transceiver device, and when the Kth communication device broadcasts its channel information, the front K-1 communication device stops transmitting the channel information. Transmitting data; during the period when the former K-1 communication device stops transmitting data, the Kth communication device broadcasts the channel information so that the communication device after K learns The communication information transmitted by the K communication device to the wireless transceiver; the first K communication devices resume the original data transmission after the Kth communication device completes broadcasting the channel information of the communication; and the Nth communication device is based on the communication device of the previous N-1 The relationship between the channel information and its own channel information determines the signal-to-noise ratio SNR _{proj of the} data transmitted by the Nth communication device; the Nth communication device adjusts the transmission rate according to the obtained noise ratio SNR _proj and transmits the signal; after a predetermined time The communication device of the wireless transceiver simultaneously ends its data transfer. The data transmission control device of claim 16, wherein the channel between the Nth communication device and the wireless transceiver (h _N ) and the channel between the front N-1 communication device and the wireless transceiver (h ₁ ~ h _{N -1} ) It is estimated that the angle θ is the angle between h _{N and the} plane formed by h ₁ ~ h _N-1 . The data transmission control device of claim 17, wherein the signal channel direction h _n is a channel vector of the communication device transmitting a signal to the antenna of the transceiver, hn=(h _n1 , h _n2 , . h _nm ), n is a natural number, m is the number of antennas of the transceiver. The data transmission control device according to claim 17 or 18, wherein the signal noise ratio SNR _proj is calculated from the signal angle θ according to the following equation: SNR _proj = SNR _ori × sin ² (θ). The data transmission control device of claim 16, wherein the third communication device transmits the data at the adjusted transmission rate without interfering with the rate at which the first and second communication devices transmit data.